steam piping questions

josephc

We are having an addition put on our home which will require a radiator added to our existing two pipe gravity/vapor low pressure steam system. The contractor brought the plumber over to scope out plumbing work and he is interested in bidding the radiator addition. Our main and the return already have capped taps from radiator(s) removed long before we moved in so I suggested we tie in there.

My question is with regards to joining of the pipe. Plumber wants to use a method that doesnt involve threading the pipe. He said he would cut the branch coming off the main and use a press fitting of some kind - I tried looking up on line and closest I come up with is megapress. Has anyone heard of this method and is it an issue in low pressure steam service?

thanks
Joe

nicholas bonham-carter

Threading the pipe is better. The various nothread methods use gaskets to seal the joint, and they may have problems sealing with the higher temperatures of steam. The problems would not be noticed in the first year, but more likely after that, so if he will give a 5 year guarantee, you are good to go.
There is a lot of expansion and contraction going on in a steam system, which would not be the case with other piping scenarios where the use of these nothread joints is standard, such as fire sprinkler systems, or hot water systems.—NBC

RomanP

Megapress gaskets are rated for low pressure steam, but NBC brings up a good point. Expansion and contraction is the reason why I don’t pipe my steam boilers in copper. I’d call your local Viega rep to get more info

newagedawn

use the taps that were capped

josephc

I contacted the viega rep and they do say low pressure 15psig and 250 F is acceptable and there is a 10 yr warranty. I'm still not entirely sold on it. I need to make sure there is a threaded transition at supply and return of radiator so that I can at least service a valve or trap in the future. Will get more info from plumber.

RomanP

Well, the call is yours. You know you can’t go wrong with black pipe and fittings, but Personally, I’d love to test megapress steam system, just to see and feel it for myself. I’m always open for new equipment, fittings or ideas.

And I’m almost positive that you will have male adapters at your valves and traps.

EBEBRATT-Ed

MegaPress is approved for steel pipe on low pressure steam. The choice is yours.
Try to find out if the plumber has any steam experience. I am sure he will say he does.

It's only one radiator but I am sure it could be screwed up. Their are many plumbers on this site that do excellent steam work....but the average plumber even if he is a good plumber may not know steam

josephc

My location is in the Albany NY area and so far have not been able to locate a "steam" person even though there are steam systems in many homes and businesses. Ill check out the site and keep asking around.
thanks
Joe

gennady

We are using megapress, and it is great, but only up to 2 ". If he means copper for steam, then it is not acceptable in my opinion.